Certain vehicles, such as ground based vehicles, favor hybrid electric technology using high voltage DC power generating as a primary power source for vehicle components. Many such applications utilize a permanent magnet generator (PMG) to generate the power due to the high available power density of permanent magnet generators. Permanent magnet generators convert mechanical input power of rotational motion into electrical output power via known interactions between the magnetic field of a permanent magnet and an armature winding, referred to herein as a “power winding”. Excitation of the generator is provided by the permanent magnets, and the strength and presence of the excitation field is determined by the configuration and strength of the permanent magnets.
In typical permanent magnet generator arrangements, the excitation of rotor flux cannot be controlled, and the permanent magnet generator may operate in an undesirable fashion during short circuit conditions.